在日常编程过程中，我们可能经常需要Copy各种数组，一般来说有以下几种常见的方法：Array.Copy，IList<T>.Copy，BinaryReader.ReadBytes，Buffer.BlockCopy,以及System.Buffer.memcpyimpl，由于最后一种需要使用指针，所以本文不引入该方法。
本次测试，使用以上前4种方法，各运行1000万次，观察结果。
- using System;
- using System.Collections.Generic;
- using System.Diagnostics;
- using System.IO;
- namespace BenchmarkCopyArray
- {
- class Program
- {
- private const int TestTimes = 10000000;
- static void Main()
- {
- var testArrayCopy = new TestArrayCopy();
- TestCopy(testArrayCopy.TestBinaryReader, "Binary.ReadBytes");
- TestCopy(testArrayCopy.TestConvertToList, "ConvertToList");
- TestCopy(testArrayCopy.TestArrayDotCopy, "Array.Copy");
- TestCopy(testArrayCopy.TestBlockCopy, "Buffer.BlockCopy");
- Console.Read();
- }
- private static void TestCopy(Action testMethod, string methodName)
- {
- var stopWatch = new Stopwatch();
- stopWatch.Start();
- for (int i = 0; i < TestTimes; i++)
- {
- testMethod();
- }
- testMethod();
- stopWatch.Stop();
- Console.WriteLine("{0}: {1} seconds, {2}.", methodName, stopWatch.Elapsed.Seconds, stopWatch.Elapsed.Milliseconds);
- }
- }
- class TestArrayCopy
- {
- private readonly byte[] _sourceBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
- public void TestBinaryReader()
- {
- var binaryReader = new BinaryReader(new MemoryStream(_sourceBytes));
- binaryReader.ReadBytes(_sourceBytes.Length);
- }
- public void TestConvertToList()
- {
- IList<byte> bytesSourceList = new List<byte>(_sourceBytes);
- var bytesNew = new byte[_sourceBytes.Length];
- bytesSourceList.CopyTo(bytesNew, 0);
- }
- public void TestArrayDotCopy()
- {
- var bytesNew = new byte[_sourceBytes.Length];
- Array.Copy(_sourceBytes, 0, bytesNew, 0, _sourceBytes.Length);
- }
- public void TestBlockCopy()
- {
- var bytesNew = new byte[_sourceBytes.Length];
- Buffer.BlockCopy(_sourceBytes, 0, bytesNew, 0, _sourceBytes.Length);
- }
- }
- }
运行结果如下：
希望以上测试对您会有所帮助。
转自：http://blog.csdn.net/jiangzhanchang/article/details/9998229